diff --git a/source/_static/code/matrix2.py b/source/_static/code/matrix2.py
index 01e654409edc8d3e1aaabce7b757b94abc15e744..b4a120dff558c6372a11ea805c82fc3bc1593d11 100644
--- a/source/_static/code/matrix2.py
+++ b/source/_static/code/matrix2.py
@@ -2,7 +2,7 @@
 def matrix_maker(ligne, col, val=None):
 	m = []
 	for i in range(ligne):
-		c = [val]*col
+		c = [val] * col
 		m.append(c)
 	return m
 
@@ -12,26 +12,27 @@ def matrix_size(m):
 	return len(m), len(m[0])
 
 def matrix_get(matrix, i, j):
-	_check_matindex(matrix,i,j)
+	_check_matindex(matrix, i, j)
 	return matrix[i][j]
 
 def matrix_set(matrix, i, j, val):
 	_check_matindex(matrix,i,j)
 	matrix[i][j] = val
 
-def matrix_print(m):
-	im, jm = matrix_size(m) 
-	for i in range(im):
-		print m[i]
+def to_str(m):
+	m_str = []
+	for row in m:
+		m_str.append('\t'.join([str(cell) for cell in row]))
+	m_str = '\n'.join(m_str)
+	return m_str
 
 
 
 #---- independant regarding matrix structure  
 def _check_matindex(matrix,i,j):
 	imax, jmax = matrix_size(matrix)
-	if (i < 0 or i >= imax) or (j < 0 or j>= jmax):
-		raise IndexError, "matrix index out of range"
-
+	if (i < 0 or i >= imax) or (j < 0 or j >= jmax):
+		raise IndexError("matrix index out of range")
 
 
 def matrix_get_line(matrix, i):
@@ -41,7 +42,8 @@ def matrix_get_line(matrix, i):
 	for n in range(jm):
 		line.append(matrix_get(matrix, i, n))
 	return line
-	
+
+
 def matrix_set_line(matrix, i, val):
 	_check_matindex(matrix,i,0)
 	im, jm = matrix_size(matrix)
@@ -56,22 +58,21 @@ def matrix_get_col(matrix, j):
 	for n in range(im):
 		col.append(matrix_get(matrix, n, j))
 	return col
-	
+
+
 def matrix_set_col(matrix, j, val):
 	_check_matindex(matrix,0,j)
 	im, jm = matrix_size(matrix)
 	for n in range(im):
 		matrix_set(matrix, n, j, val)
 	
-	
-	
+
 if __name__ == '__main__':
 	m = matrix_maker(5, 3)
 	matrix_set(m,0, 0, 1)
 	matrix_set(m,0, 2, 2)
 	matrix_set(m,4, 0, 12)
 	matrix_set(m,4, 2, 15)
-	matrix_print(m)
-	print "get line 0",  matrix_get_line(m, 0)
-	print "get col 0", matrix_get_col(m, 0)
-	
+	print(to_str(m))
+	print("get line 0",  matrix_get_line(m, 0))
+	print("get col 0", matrix_get_col(m, 0))